Originally Posted by Riou;12128883
They can increase the polygon count instead. Tessellation is like turning a cube into a sphere. You could use more polygon and less tessellation factors to get the same end result.

So then the question is: Is it somehow easier for devs to use tessellation rather than increasing polygon count?

This is a cool demo, but it's not really showing off anything "new", well.. new for games, it's really just a combination of current technology to make a pretty sweet system. Displacement maps have been around for ages, however Pixar has come out with a new system for displacement maps that gives more possibilities then the current system.